interface USB{
    void work();
    void stop();
}
class Mouse implements USB{
    public void work(){
        System.out.println("我点点点");
    }
    public void stop(){
        System.out.println("我不能点了");
    }
}
class UPan implements USB{
    public void work(){
        System.out.println("我存存存");
    }
    public void stop(){
        System.out.println("我走了");
    }
}
public class Main{
    public static void main(String[] args){
        USB usb1 = new Mouse();
        usb1.work();
        usb1.stop();
        USB[] usbs = new USB[2];
        usbs[0] = new UPan();
        usbs[1] = new Mouse();
        for (int i = 0; i < 2; i++) {
            usbs[i].work();
            usbs[i].stop();
        }
    }
}